Departments of ^aGenetics

^bPediatrics

^cDepartment of Obstetrics and Gynecology, Division of Maternal Fetal Medicine

^dDepartment of Medicine, and UAB Osteoporosis Prevention and Treatment Clinic, Division of Clinical Immunology and Rheumatology, the University of Alabama at Birmingham, Birmingham, Alabama, USA

^eResearch Centre of Ste-Justine Hospital, Department of Medicine, University of Montreal

^fDepartment of Medicine, University of Montreal, Montreal, Quebec, Canada

* Maria Descartes and Kitiwan Rojnueangnit: co-first authors.

Correspondence to Maria Descartes, MD, Department of Genetics, University of Alabama at Birmingham, Kaul 210A 1720, 2nd AVE South, Birmingham, AL 35294-0024, USA Tel: +1 205 934 4973; fax: +1 205 975 6389; e-mail: [email protected]

Received November 12, 2013

Accepted February 4, 2014